The present invention relates to an aqueous dispersion of polymer encapsulated TiO2 particles and a process for preparing them. This dispersion is useful for plastics and coatings formulations.
Opacifying pigments such as TiO2 provide opacity (hiding) for coatings and for plastics to conceal the undersurface. It is believed that the efficiency of the pigment is related to the spacing of the pigment particles in the coating or plastic. Improvements in spacing can be achieved, for example, by using sulfur acid-functional polymers as dispersants for the pigments in combination with other polymers that at least partially encapsulate the pigment, as disclosed in US Pat. Pub 20100/298483. It would be desirable to find improved opacifying pigment compositions and more efficient ways of making them.